     (world-append (update w :configs #(subvec % 0 (dec (count %))))
                   (heval/recache-trs new-defs (current-config w)))))
 
-(defn world-update-desc! [desc]
+(defn world-update-desc! [world desc]
   (update-world! world
                  (fn [w]
                    (world-update-desc w desc))))

                   :walls (:walls new-world)
                   :seen-polys {}
                   :explored #{}
                   :seen-configs #{})
        w (update w
                  :configs
                  (fn [cfgs]

                                     has (:objects cfg)
                                     polys (apply concat (vals (:seen-polys wld)))]
                                 (sab/html [:div {:style {:backgroundColor "blue"
                                                          :width           (+ container-w 20)
                                                          :height          (+ container-h 20)
                                                          :position        "relative"
                                                          :overflow        "scroll"}
                                                  :onScroll
                                                         (fn [scroll-evt]
                                                           (let [n (.-target scroll-evt)]
